Transmission and control

ABSTRACT

A transmission and control having a fluid or mechanical drive input in the forward gear ratios and a mechanical drive input in reverse gear ratios. The control, for controlling the engagement of a low-reverse brake when the transmission operation is changed for neutral or forward or reverse drive, has a shift valve responsive to a relay valve controlled by a manual valve. The relay valve responds to movement of the manual valve from neutral to forward or reverse drive to actuate the shift valve thereby directing fluid to engage the low-reverse brake. The control may be operated to selectively provide a mechanical input drive in the first ratio also.

O United States Patent 91 [111 3,713,354

Edmunds 1 Jan. 30, 1973 [54] TRANSMISSION AND CONTROL PrimaryExaminer-Arthur T. McKeon [75] Inventor. John O. Edmunds, lndianapolis,lnd. Almmey w E. Pinker. A. M. Heiter and D. F [73] Assignee: GeneralMotors Corporation, Scherer Detroit, Mich. 221 Filed: Jan. 8, 1971 ,[57]ABSTRACT A transmission and control having a fluid or mechani- [211104367 cal drive input in the forward gear ratios and a mechanical driveinput in reverse gear ratios. The con- 52 u.s. Cl. ..74/732, 74/753,74/688, for controlling the engagement of a low-reverse 75 74/869 brakewhen the transmission operation is changed for 51 Intl Fl6h 47/00 F16h57/10 47 0 neutral OI forward 0! TCVCX'SC drive, has a Shift valve [58]Field of Search ,1 731 688 732 responsive to a relay valve controlled bya manual valve. The relay valve responds to movement of the [56]Reterences cued manual valve from neutral to forward or reverse drive toactuate the shift valve thereby directing fluid to en- UNITED STATESPATENTS gage the low-reverse brake The control may be operated toselectively provide a mechanical input 3,096,666 7/1963 Christenson etal ..74/6 5 d i i h fi ratio 3,252,352 5/1966 General et al. ..74/6 53,523,468 8/1970 Kepner ..74/7 9 5 Claims, 6 Drawing Figures fig? (17 .4

PATENTEUJAH 30 I873 SHEET 1 [IF 5 GAS TURBINE ENGINE By .6/11: a 'fiZQZZZ ATTORNEY PATENTEDJAII 30 I975 3.713.354

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PRESSURE REGULATOR ATTORNEY PATENTEDJAHSO I973 3,713,354

SHEET 5 0F 5 i I Q 4? Z gin/11 w a: 1Z5 2!! W fiuuuuu' -M ."H I:- 792135 MAIN PRESSURE Ex 13? /17 125 H gr n r 'll 3 1| 11 Y! Y zzr 231 a:

. .n S m Z3 Z1! 1 (Hi iocKuP VALVE EX' K J J 14 If! w a TO LUBE v #1 a 2,fll' I i i w COUPLING LUBE I BYPASS v REGULATOR 11; K coo| ER ATTORNEYTRANSMISSION AND CONTROL This invention is related to multiratiotransmissions and controls and more particularly to transmissions havinga fluid or mechanical drive input in all forward ratio and a mechanicaldrive input in reverse.

This invention is adaptable for use with a gas turbine engine whereinthe power turbine is not continuously driven during operation. Withengines of this type it is possible to stall the power turbine when thevehicle being driven is stationary with the transmission conditioned fora forward or reverse drive. The present invention however includes afluid coupling drive connected between the gas turbine engine and theplanetary gearing to permit the power turbine to rotate when thetransmission gearing is conditioned for forward first speed drive.

When the transmission is in neutral the control system is operative todisengage all of the friction drive establishing devices associated withthe planetary gearing so that the engine and coupling rotate freely. Amanual selector valve is provided to permit the operator to shift fromneutral to a forward or reverse drive. When a forward or reverse driveis selected by the operator the manual valve provides a shift signal toa neutral-first relay valve which causes the valve member to shiftagainst a bias spring. A neutral to first shift signal valve controls apressure bias on a neutral to first relay valve such that when the shiftsignal valve is shifted in response to the selector valve the pressurebias on the relay valve is exhausted permitting the relay valve to moveto the drive position. In the drive position the shift valve directsfluid pressure to the lowreverse brake in a transmission to conditionthe transmission for a forward drive when the reverse clutch isdisengaged or for a reverse drive when the reverse clutch is engaged. lnfirst gear forward, in the preferred embodiment, the fluid couplingprovides a fluid drive between the engine input and the planetarygearing to provide a slipping connection therebetween when the vehicleis initially accelerated. After the vehicle has reached a predeterminedspeed a lock-up clutch in the transmission is engaged to provide adirect mechanical connection from the engine to the planetary gearing.The lock-up clutch may be selectively engaged in first gear also. Inreverse drive a fourth speed or reverse clutch is engaged to provide amechanical drive directly between the engine and the planetary gearing.

It is an object of this invention to provide in an improved transmissionand control a planetary gearing arrangement having a fluid drive in thefirst forward drive ratio and a mechanical drive input in all otherdrive ratios including reverse.

lt is another object of this invention to provide in an improvedtransmission and control a planetary gearing arrangement having a fluidinput in forward drive and a mechanical input in reverse drive andcontrol valve means for engaging a drive establishing device when eithera reverse or forward drive condition is established from a neutralcondition.

These and other objects and advantages of the present invention will bemore apparent from the following description and drawings of thepreferred embodiment in which:

FIG. 1 is a block diagram showing the arrangement of FIGS. 2, 3, 4, and6; and

FIGS. 2, 3, 4, 5 and 6 when arranged according to FIG. 1 schematicallyshow the gearing and control of the transmission. 1

Referring to the drawing, FIG. 2 shows a gas turbine engine 9 drivingthe power train having an input shaft 10 driving a rotary hydrauliccoupling housing 12 which drives the pump 14. The pump hydrokineticallydrives the turbine 15 which is connected by a hub 21 to the couplingoutput shaft 22.

The four speed gear unit generally designated 34 has three planetarygear sets to provide four forward speeds and a reverse which arehereinafter referred to as first to fourth and reverse. The first gearset of the four speed unit 34 has planetary pinions 36 mounted on acarrier 37 and meshing with sun gear 38 and ring gear 39, the secondhaving pinions 41 rotatably mounted on carrier 42 and meshing with sungear 43 and ring gear 44 and the third having planetary pinions 46mounted on the carrier 47 and meshing with sun gear 48 and ring gear 49.

A forward clutch 51 is engaged in all forward ratios except first andconnects the coupling output shaft 22 to a pump hub 50 to effectivelylock-up the coupling to provide a mechanical drive to the sun gear 38 ofthe first gear set and through hub 54 the ring gear 44 of the secondgear set. The turbine 15 drives the sun gear 38 and ring gear 44 throughshaft 22 when first gear is engaged. The forward clutch 51 has plates 55mounted on a drum 56 driven by the rotary hub 57 drive connected to hub50. The hub 57 has a cylinder 58 formed therein for piston 59. On thesupply of fluid by lock-up apply line 281 to the cylinder 58, the piston59 engages the plates 55 and the plates 61 which are connected by a hub62 to the coupling output shaft 22. Fourth speed clutch 63 connects thepump hub 50 to the secondary input shaft 64 which drives the sun gears43 and 48 of the second and third gear sets and cooperates with clutch51 to lock all transmission units for 1:1 drive to the output 99. Thefourth speed clutch 63 has an input drum 66 formed as a continuation ofdrum 56 to drive input plates 67. The output plates 68 are connected bydrum 69 and hub 71 to input shaft 64. The hub 71 has a cylinder 72formed therein for the piston 73 and on the supply of fluid to thecylinder by fourth clutch apply line 432, piston 73 engages the platesto effect a drive from the pump hub 50 to the secondary input shaft 64to drive sun gears 43 and 48. The shaft 64 may also be held by the thirdspeed brake 76 which has fixed plates 77 and rotary plates 78 driveconnected through drum 69 and hub 71 to shaft 64 to hold shaft 64 andsun gears 43 and 48. When fluid is supplied by third apply line 436 tothe cylinder 79 formed in housing 19 to move the piston 81 to applyplates 77, 78 the brake 76 is engaged to hold the shaft 64 and the sungears 43 and 48. The second speed brake 82 has a plurality of fixedplates 83 fixed to the housing 19 and rotary plates 84 connected by ahub 85 to the carrier 47 of the third gear set. When fluid is suppliedby second apply line 419 to the cylinder 86 formed in housing 19, piston87 moves to engage'the plates 83, 84 and holds the carrier 47. The firstand reverse brake 89 has a plurality of fixed plates 91 secured tohousing 19 and rotary plates 92 drive connected to ring gear 39. Whenfluid is supplied by first speed brake apply line 309 to the cylinder 93formed in housing 19 to move the piston 94 and engage plates 91, 92 thering gear 39 of the first gear set is held.

In forward drive with clutch 51 released the coupling provides aslipping connection between the input shaft and the sun gear 38. Thispermits the power turbine of engine 9 I to rotate when the vehicle isstationary. However, when the transmission is in reverse, the powerturbine is stalled when the vehicle is stationary. When the vehicle ismoving in reverse the pump 14 and turbine 15 of the coupling rotate inopposite directions since the pump is driven forward by the engine 9 andthe turbine is driven in reverse by the ring gear 44 and the sun gear38. I

CONTROLS The brakes and clutches are engaged as indicated by X on thefollowing chart and the others disengaged to provide four, forwardspeeds and reverse.

Referring to FIG. 6, the fluid exhausted from the control andlubrication system collects in the sump 111 in the lower portion of thetransmission housing. A gear pump 112 draws fluid through the suctionfiller 118 and line 116 and delivers fluid to the main line 117 and isregulated by the main pressure regulator valve 119. The main pressureregulator valve 119 has a valve element 121 having lands a, b, c, d, ofequal diameter and a larger land e located in a stepped bore 122. Thevalve element 121 is biased to the closed position shown by a spring 123mounted on a combined spring seat and stop element 124 which is atubular member to limit valve movement and spring compression which hasa flared end 125 providing a seat for the spring and abutting snap ring126 to retain the seat element and spring in spring chamber 130 ventedto exhaust. The main line 117 has a branch 127 connected between thelands 0 and d and through port 128 and the bore 129 through the valve tothe port 131 between the lands a and b and through a restriction to theport 132 at the end of the valve element to provide hydraulic bias inchamber 133 opposing the spring to regulate the main line pressure at apredetermined value. Regulated pressure is supplied by port 132 to thespace between the lands a and b toprevent leakage from chamber 133 tothe space between lands b and c'vented by exhaust 134. The forwardknockdown pressure line 135 is connected at the step between lands d ande to reduce the regulated pressure to i.e. 150 psi in all forward drivepositions while pressure in reverse drive is higher, i.e. 250 psi.Excess main line pressure in line 117 and chamber 133 moves theregulator valve element 121 to the exhaust position exhausting branch127 to overage line 136 which feeds the coupling through a coupling feedline 146. The cooler outlet line 154 is connected to the lubricationlube regulator valve 139 which has a valve element 141 biased to aclosed position by a spring 142 and is closed when the overage pressuredoes not exceed a low value to first supply lubrication line 138. Whenthe lubrication pressure is sufficient, overage pressure exceeds apredetermined value, i.e., 40 psi and the valve 139 opens to connectcooler outlet line 154 to exhaust. When coupling feed pressure exceeds apredetermined low pressure, excess fluid in coupling feed line 146 movesvalve element 152 against the bias spring 153 of coupling bypass valveand lube pressure to exhaust excess coupling feed pressure to the cooleroutlet line 154. The coupling outlet line 156 is connected in FIG. 6through the cooler 160 to the cooler outlet line 154 where the pressureis limited by the lube regulator valve 139.

DETENT VALVE A through detent valve 162, FIG. 5, which has a valveelement 163 having equal diameter lands a, b and 0 located in a bore 164and is biased in an opening direction by a spring 166 located in thespring chamber 167 vented by exhaust 168. Main line pressure 117 isconnected through restricted passage 169 to a chamber 171 to act on theinactivating piston 172 to normally engage valve element 163 and hold itin theextreme right position against the stop element 173 so that thethrough detent valve does not deliver pressure to the detent line 174.When the throttle pedal 176 is past the full throttle position, itcloses switch 177 connecting a grounded power source 178 to the solenoidvalve 179 which opens the port 180 to exhaust 181 to vent fluid inchamber 171 to permit the detent valve 162 to regulate pressure. Theregulated pressure supplied from main line 117 via branch 182 to thespace-between lands a and b to the branch 183 of detent line 174 andthrough restricted branch 184 to the space between the piston 172 andvalve element 163 to initiate regulation of detent line pressure at apredetermined low value i.e. 38 psi, determined by spring 166. Excesspressure will move the valve element 163 against the spring 166 andconnect the detent line to exhaust 186.

SELECTOR VALVE The manual selector valve 191 has avalve element 192having equal diameter lands a, b and c. In all valve positions, mainline 117 is connected to the signal feed line 194. In neutral the mainline is also connected to the forward knockdown line 135. The reverseselector line 195 is connected to exhaust 196. The drive one line 198;drive two line 199 and the drive three line 201 are connected to exhaust202. The drive four line 203 is connected via hold feed line 204, holdregulator valve 209, hold pressure line 217, drive three line 201 toexhaust 202.

On movement of the selector valve 192 to the reverse position, land ccloses exhaust 196 and opens port 206 to connect main line by fast feedball check valve 207 and slow return restriction 208 to the reverseselector line 195. The forward knockdown line 135 is also exhausted viahold feed line 204. On movement of the selector valve to drive fourposition, DR4, reverse is exhausted and in addition to feeding feed line194 and forward knockdown line 135 as in neutral, the drive four line203'is fed while the other drive lines remain connected to exhaust as inneutral. in drive three position, DR3, the main line 117 additionallyfeeds the hold feed line 204 and blocks the exhaust of drive three feedline 201. In drive two position, DR2, the main line feeds the same linesand interconnects drive two feed line 199 and drive three feed line 201.In drive one position, DR1, the main line feeds the same lines and thedrive one feed line 198, drive two feed line 199 and drive three feedline 201 are interconnected.

HOLD REGULATOR VALVE The hold regulator valve 109 regulates the pressuredistributed by the drive one, two and three feed lines and has a valveelement 211 having equal lands a, b and c located in a bore 212. Aspring 213 located in a spring chamber vented by exhaust 214 biases thevalve 211 to the open position shown. In the open position shown, thehold feed line 204 is connected through restriction 216 to the spacebetween lands b and c and supplies hold pressure supply line 217 whichis connected to the drive three line 201. This hold pressure supply line217 is also connected by restricted passage 218 to the closed chamber219 at the end of bore 212 to act on land a of the valve element tooppose the spring bias. The pressure in chamber 219 moves the valveagainst the spring to connect line 217 to exhaust 221 or feed line 204to regulate hold pressure at a valve intermediate main line pressure anddetent pressure, i.e. 45

GOVERNOR The governor valve 223 has a valve element 224 having equallands a, b, and c mounted in a bore 225 and is rotatably driven by agear 226 driven from output shaft 99 by a spline connector 227 whichpermits axial movement of the valve element 224 under the influence ofthe rotating governor weights 229 and secondary weights 231 whichprovide a stepped pressure varying with output or vehicle speed. Fluidpressure supplied by the signal feed line 194 through filter 233 isconnected between lands a and b and by a passage 234 through the valveelement to the end valve element 224 to act on the end of the valveelement to move it to an exhausting position connecting governor signalline 236 to exhaust 237 against the opposing force of the governorweight. The force of the governor weight overcomes the pressure to movethe valve to the left connecting signal feed line 194 to governor line236 and closing exhaust 237. The one way check valve 238 permits fastflow of the governor signal pressure to the shift valves and the returnrestriction 239 only permits slow return flow so the governor pressureline has fluid flow to supply without pressure drop, the expandinggovernor pressure chambers when shift valves upshift and reduce returnflow to prevent sharpreduction of governor pressure due to drive lineshock.

MODULATOR PRESSURE REGULATOR The modulator pressure regulator 241, FIG.5, provides a pressure inversely proportional to torque demand and has avalve element 242 having equal lands a and b mounted in a bore 243. Thespring 244 located in a spring chamber 245 vented by exhaust 246 biasesthe valve element to the open position connecting signal feed line 194between the lands to the modulated signal line 248 which is connected bya restrictive passage 249 to the chamber 250 at the end of the bore 243to act on the end of land b to bias the valve element to connectmodulator line 248 between lands a and b to exhaust 251, to regulate themodulated signal pressure inversely proportional to engine load or theforce delivered by compressor discharge actuator 253.

The modulator pressure regulator valve 241 is controlled by an actuator253 consisting of an actuator stem 261 which is reciprocally mounted ina bore 262 in the end wall of the valve body which is vented by exhaust264. A chamber 255 is adjacent the end of stem 261 and is connected tothe compressor of the gas turbine to permit compressor dischargingpressure, which is proportional to engine power developed, to act on thestem 261. The stem 261 engages a pin 265 reciprocally mounted in a bore266 in the valve body to engage the valve element 242. The force of theactuator stem 261 is proportional to the compressor discharge and thusincreases with increasing compressor discharge pressure and acts throughthe stem 261 and pin 265 on the valve element 242 and with the regulatedpressure in opposition to the valve spring 244 to provide a regulatedpressure inversely proportional to actuator force, or compressordischarge pressure.

LOCK-UP VALVE The lock-up shiftvalve 271, FIG. 6, has a valve element272 having lands a, b and c reciprocally mounted in a stepped bore 273.The governor pressure line 236 is connected to closed chamber 274 to acton the end of land a to bias the valve against the bias of spring 276located in a chamber vented by exhaust 277 and having a stop and springseat member 278. Port 285 between lands b and c is exhausted. In sometransmission designs, it is desirable to have the lock-up valve shiftedin drive one. In these transmissions the drive one line 198 is connectedwith the port 285 so that line pressure will upshift the lock-up valve.With the lock-up valve in a downshift position shown, lock-up apply line281 is connected to exhaust 282 to disengage the forward lock-up clutch51. This valve is upshifted by governor pressure in an upshifteddirection and overcoming the bias of the spring in a downshiftdirection. The lock-up valve provides the shifts at a fixed outputspeed. In the upshifted position main pressure in lock-up feed line 283is connected between the lands a and b of the upshifted lock-up valve tolock-up clutch apply line 281 to engage the lock-up clutch. The land bis slightly larger than land a so the main line pressure connected tothe lock-up clutch provides a hysteresis force, so downshifts are atlower speeds. The exhaust 282 then being closed. The exhaust 284 permitsleakage fluid to escape to prevent main line leakage affecting modulatorpressure.

NEUTRAL-ONE SHIFT SIGNAL VALVE The neutral-one shift signal valve 286,FIG. 4, controls the neutral to first shift by controlling theengagement of the first brake 89. The shift signal valve 286 has a valveelement 287 having equal diameter lands a and b slidably mounted in abore 288 and a plug 290 slidably mounted in bore 288. The plug 290 andvalve 287 are biased by reverse pressure from line 195 connected tochamber 289 at the end of bore 288 to act on the plug 290 or by drivefour pressure in line 203 acting on land a between valve element 287 andplug 290 to move the valve element against the bias of spring 291 toexhaust the N-l shift signal line 292 to permit engagement of the firstand reverse brake 89 by the neutral-one relay valve 298. When theselector valve 191 is in neutral the spring 291, the lines 203 and 195are exhausted and valve element 287 is biased by spring 291 to connectline 292 with pressure in line 307 to shift the neutral-one relay valve298 to prevent engagement of brake 89.

NEUTRAL-ONE RELAY VALVE The neutral-one relay valve 298, FIG. 4, has avalve element 299 having equal diameter lands a, b and c mounted in abore 301 and biased to the first drive speed position by the spring 302mounted in a spring chamber 303 vented by exhaust 304. With the valveelement in the first drive speed position shown, the first apply line309 is connected to branch 308 of line 307. Main line pressure issupplied from the one-two shift relay valve 378 via line 307 and itsbranch 308 between the lands b and c to the first speed apply line 309which is connected to the first brake cylinder 93 to establish firstspeed drive. When fluid is supplied by the neutralone shift signal valve286 to the neutral-one shift signal line 292 to the chamber 311 at theend of valve element 299 acting on land a, the valve is moved againstthe spring bias to the neutral position connecting the first apply line309 to branch 314 of exhaust line 306 while land b blocks branch 308 ofline 307.

ONE-TWO SHIFT SIGNAL VALVE Automatic shifting between first to fourthspeed forward drives is provided by a speed and engine load signalcontrolled shift signal valve, one for each speed change, each having anassociated relay valve. The shift and relay valves for each speed changeare similar but are individually described with the connections and thenthe basic function of operation is discussed.

The one-two shift signal valve 316, FIG. 4, has a valve element 317having land a and larger land b in a stepped bore 318 and a controlelement 319 having lands a, b and c of increasing diameter from a to cmounted in a stepped bore 321.The land b of valve element 317 is largerthan land a so that when the valve is moved from the downshift positionshown in FIG. 4 to the upshift position connecting main line 117 to theone-two signal line 322 for a shift to second speed, there is an addedhysteresis force in an upshift direction on the valve. In the downshiftposition shown, the onetwo signal line 322 is connected to exhaust 323and this hysteresis force is dropped. In both downshift and upshiftpositions, governor pressure from line 236 enters chamber 324 at the endof bore 318 and acts on land a of valve element 317 in an upshiftdirection. Also modulator pressure line 248 is connected to the steppedbore between the large land and the smaller land b of control element319 to also provide an upshift direction force. Both the governor andmodulator upshift direction forces are opposed by the downshiftdirection force of spring 325 which is mounted on a suitable spring seatand stop assembly 326 in a spring chamber 327 vented by exhaust 328.When governor pressure and modulator forces overcome the spring force,both valve elements upshift and the modulator pressure from line 248 isalso connected between land a and b of the control valve element 319.Since land b is larger than the land a there is an additional area andupshift force after upshifting to control the downshiftv The two-onedownshift line 329 may supply either hold pressure from the drive oneline 198 of detent pressure from detent line 174 and is connected viabranch 330 to hold the shift valve element 317 in the downshift positionwhen downshifted or via branch 331 when the valve element is upshiftedto downshift the shift valve element at a predetermined speed. Theregulated hold pressure supplied is insufficient to downshift above apredetermined speed for a proper shift.

The two-one downshift line 329 is supplied in a detent position of thethrottle pedal by detent valve 162 and detent line 174. If the slightlyhigher hold pressure from hold regulator valve 209 is connected by theselector valve 191 in the drive one position to drive one line 198, theone-two shuttle valve 332 blocks detent line 174 and connects holdpressure from drive one line 198 to downshift line 329. The shuttlevalve 332 has a ball 333 located in a chamber 334 having a bottomsurface having depressed seat port 335 at the entry of detent line 174to the chamber and closely adjacent depressed seat port 336 at the entryof drive one line 198. The downshift line 329 is connected to chamber334 by a port that is wide and positioned so it cannot be blocked byball 333. When pressure is supplied to one of seat ports 335 or 336, theball will seat in and close the other. The chamber has a rounded uppersurface particularly at the ends to guide the ball into the seat portsand the height of the chamber between the seat ports should be onlyslightly greater than the ball diameter.

TWO-THREE SHIFT SIGNAL VALVE The two-three shift signal valve 341 has avalve element 342 having lands a, b and c of increasing diameter from ato c in a stepped bore 343 and a control element 344 having lands a, band c of increasing diameter from a to c in a stepped bore 345. In boththe up and down shift positions of the shift valve, the governorpressure line 236 is connected to the chamber 346 to provide an upshiftdirection force and the modulator pressure line 248 is connected betweenthe lands b and c of control element 344 to act on the excess area ofland c to provide an upshift force against the downshift direction forceof spring 347 mounted on a seat assembly 348 in the spring chamber 349which is vented by exhaust 351. Exhaust 352 vents a space between landsb and c of valve element 342. Exhaust 353 exhausts the twothree signalline 354 with the valve element 342 in the downshift position shown sothere is no two-three signal pressure for a shift to third. On anupshift exhaust 353 is closed and main line 117 is connected to thetwo-three signal line 354. With the shift valve 342 and control valve344 in the downshift position shown or upshift position, governorpressure from line 236 in chamber 346 acting on land a and modulatorpressure from line 248 acting on land c of control valve 344 provides anupshift direction force against the downshift force of spring 347 toprovide upshifts. When the governor pressure and modulator pressureovercome the spring force, the shift valve, 342 and control valve 344move to the upshift position. The main line pressure acting on land bwhich is larger than land a provides an upshift hysteresis force andmodulator pressure acting on land b provide an added upshift force toprovide downshifts at speeds lower than upshift speeds. The three-twodownshift line 355 in the downshift position of the shift valve and thebranch 356 in upshift position of the shift valve is connected to thevalve bore between the shift valve element 342 and the control valveelement 344, for downshifting the-shift valve element-whensupplied withhold or detent pressure. The detentpressure line 174 and the holdpressure via drive two, line 199. are connected to the two-three shiftshuttle valve 357 which has the same structure'as the onetwo shuttlevalve 332 and thus has the same reference numbers. primed. Whenthethrottle pedal is in detent position providing detent pressure in1ine.1-74 shuttle valve 357 connects this pressure to the three-twodownshift line 355.b.ut if the selector valve 191 is in drive'three ortwo positions providing hold pressure in line 199 this pressure issupplied to downshift line 355 and detent pressure blocked.

THE THREE-FOUR SHIFT SlGNAL'V'ALVE Thethree-four shift signal valve 358,FIG. 4, hasa shift valve element 359 havingv lands a, band located in.astepped bore.36l and a control valve element 362 having lands a, b and cin a stepped bore 363. The lands of both valve elements havesequentially increasing diameters from ato c. Both valveelementsare'biased tothe downshift position by a-spring364 located inaspring chamber 365 vented by exhaust366. The-spring is seatedon anadjustable seat 367 and having a'stop pin 368 limiting valve movement.In the downshiftposition, shiftvalveelement 359 blocks mainline 117 andconnects the-.three-four shiftsignal line 3731 to exhaust 372. In thisposition 1 governor pressure acting in chamber 373 on the land aof'valve element 359 and modulator pressure line 248 acting on the landc of control valveelement 362 provide a force in the upshift directionagainst the downshift direction force of the spring 364. When governorand modulator pressure overcome the spring force, the valve elementsupshift. ln upshift position land a of valve element 359 blocks exhaust.372, main line 117 is connected to the threefour shift signal line 371and the main line pressure between lands a and b acts on the largerarea-of land b to provide a primary additional upshift hysteresis force.In addition, modulator pressure also acts on land b of control valveelement 362 to provide an additional upshift force causing downshifts atlower speeds. The exhaust 374 vents the valve bore between the downshiftline 375 and main line 117. Hold or detent pressure in three-fourdown-shift line 375 and its branch 37.6 is connected between the valveelements when in the downshift and upshift position respectively toposition valve element 359 in a downshift position at proper speeds.When detent pressure is supplied to line 174 the three four shuttlevalve 377 connects it to fourthree downshift line 375 unless theselector valve is in drive one, two or three position and supplies thehigher hold pressure to drive three line 201 which is then connected todownshift line 375 and detent pressure is blocked. This shuttle valve377 has the same structure and operation as shuttle valve 332 so theparts have the same reference numerals double primed.

ONE-TWO RELAY VALVE The one-two relay valve'378, FIG. 3, has a valveelement 379 having equal diameter lands a, b and 0 located in a bore 381and is biased to the first speed position shown by a spring 382 seatedon the spring under the bias of spring'39 6' in vented chamber 397 whenthe'pressure' in main line and drive four line 203 is insufficient forproperly operating the transmission and open whenthe pressureissufficie'nt. The'valve will close momentarilyduri'ngsh'ifts involvingengagement of second, third and 'fourth in-forward drives to maintainsufficientmain' line feed pressure to the modulator valve 24'1 andgovernor valve-223. The'restriction 391 provides an exhaust connectioninneutral position of the-selector valve.

Relay valve 378 in the first speed'position shown, connects'the-one-twoshift line-398to'exhaust line'306, blocks priority drive fou'r'line'39'3, con'nectsthe main line "1 1-7 via*restriction 39 9 betweenthe lands b and c to the line 307, blocks restricted 'bran'ch40 2'ofexhaust line 306 at the'land'c and connects reverse drive'line from themanual selector valve'adjacent land c to the'spring chamber 384'whic'hisclosed sincepassa'ge 387-is blocked.When the'o'ne-two shiftsignalvalve 32 1 provides pressure in the one-two signal 'line 322 tosupply-fluid to the closed chamber 401, valve element 379 is m'ovedagainst'the 'biasof the spring except in reverse to the second speedposition. Then spring chamber 384 is connected via passage 387 toexhaust line 306, priority drive four line is connected to the one-twoshift line 398,main'line 117 is blocked'by land b,the line 307 isconnected via restrictedbran'ch 402 to exhaust line 306 and reverse line195 isblocked by land TWO-THREE RELAY VALVE The two-three relay valve406 has a valve element 407 having equal diameter lands *a, b and '0located in a bore 408 and biased by a spring 409 to the downshift orsecond speed position shown in FIG. 3. The spring is seated on a seatand pin assembly 411 in a chamber 412 vented by exhaust 414. When therelay valve is biased by the spring to the second speed position, thetwo three shift feed line 415 is connected between lands a and b viabranch 416 to exhaust line 306, one-two shift line 398 has unrestrictedbranch 417 blocked by land b and the restricted branch 418 connectedbetween lands b and c to the second brake line 419 and restrictivebranch 421 of the exhaust line 306 is blocked by land 0. When thetwo-three shift signal valve 341 supplies the two-three shift signalline 354 pressure to chamber 422, the two-three relay valve elementmoves against the spring 409 to the stop pin and exhaust branch 416 isblocked by land a. The one-two shift signal line398 via branch 417 isconnected to the two-three shift line 415, the restricted branch 418 isblocked by land b and the second brake line 419 is connected viarestricted branch 421 to exhaust line 306.

THREE-FOUR RELAY VALVE The three-four relay valve 424 has a valveelement 425 having equal diameter lands a, b and located in a bore 426and is biased by a spring 427 to the third position shown in FIG. 4. Thespring is located in the v chamber 428 vented by exhaust 429 and seatedon a seat and valve stop assembly 431. When the valve element 425 isbiased to the third position shown by the spring 427, reverse drive line195 is connected between the lands a and b to the fourth clutch lines432, the twothree shift signal line 415 has restricted branch 434blocked by the land b and restricted branch 435 connected between landsb and c to the third brake line 436 and the exhaust line 306 connectedby restriction 437 is blocked by land 0. When the three four shiftsignal valve 358 provides a signal pressure in the threefour shiftsignal line 371 to the chamber 438, this pressure acts on land a movingthe valve to the fourth speed position. Then reverse drive line 195 isblocked by land a, .twothree shift line 415 is connected by restrictivebranch 434 to the fourth clutch line 432 and branch 435 is blocked byland b and the third brake line 436 is connected via restriction 437 toexhaust line 306.

TRIMMER REGULATOR VALVE The trimmer regulator valve 441, FIG. 3, has avalve element 442 having equal diameter lands a, b, c and larger land dlocated in a stepped bore 443 and is biased to the feed position shownby a spring 444 seated on an abutment and stop pin assembly 446 locatedin a spring chamber 447 vented by exhaust 448. With the valve element442 in the feed position shown, main line 117 branch 451 is connectedbetween the lands b and c to the trimmer regulated pressure line 452which is connected by branch 453 which may be restricted to the closedchamber 454 to act on the end of land a and oppose the spring bias andregulate the pressure. When the trimmer regulated pressure exceeds theregulated value, it will move the valve element 442 to the leftconnecting trimmer regulator pressure line 452 between lands a and b toexhaust 456. The

modulator pressure line 248 is connected between the lands c and d toact on the unbalanced area of land d opposing the spring. Increasingmodulator pressure provides a proportionately reduced trimmer regulatorpressure. Since modulator pressure varies inversely with engine load andis a maximum at idle and reduces to zero at a high throttle position,the trimmer regulator pressure sure is low at idle or at low torquedemand values and increases proportionately to increasing torque demandto a high torque demand where. the highest trimmer regulator pressure isdetermined by the spring force and the area of land a of trimmerregulator valve element 442.

TRIMMER VALVES The first and reverse drive trimmer valve 461 has atrimmer regulator element 462 having a small land a and large land blocated respectively in small bore 463 and large bore 464. The firstbrake apply line 309 is connected to the end of the bore 463 and acts onland a to bias the valve to the right to the open position connectingfirst brake apply line 309 to exhaust 467 to reduce the pressure. Firstbrake apply pressure from line 309 is also continuously connectedthrough restriction 468 to the space 469 between the regulating valveelement 462 and an actuator plug 471 which is shown seated on a stopmember 472 fully compressing the spring 473 located in a closed chamber474 having trimmer regulator pressure connected thereto at a port 475below the stop and thus never blocked by plug 471. When line 309 isvented, spring 473 is extended with plug 471 engaging regulator valveelement 462. On the initial supply of fluid to the first brake by firstbrake apply line 309, pressure acts on regulator valve element 462 andis regulated at a low pressure value determined by the trimmer regulatorpressure which increases with increasing torque demand and the minimumspring force at full height in the valve assembly. At the -same timefluid slowly flows through restriction 468 to fill and enlarge the space469 to gradually separate the regulator valve element and plug so thatthe spring 474 is more and more compressed to gradually increase theregulated pressure at a rate determined by the restriction and springrate until the maximum regulated pressure is provided with the valveelements in the position shown for gradual engagement of the frictiondevices. Then the pressure quickly increases to main line pressure. Thevalve will remain in this position until the first brake apply line 309is exhausted and the valve will return to the initial position. The useof trimmer regulator pressure makes it possible to individually set thelow pressure and rate of pressure rise to meet the requirements of eachfriction device with the same valve structure and springs fittingtherein.

The second speed trimmer valve 476 similarly has a regulator valveelement 477 having small land a and large land b respectively located insmall bore 478 and large bore 479. Second brake pressure in line 419 isconnected by branch 481 to the end of bore 478 and acts on the land a tomove the regulator valve 477 and the plug 482 against bias of spring 483and trimmer regulator pressure from line 452 and port 489 in chamber 487to connect line 481 to exhaust 488 to reduce the pressure. The stopelement 484 limits movement of the plug 482 and compression of thespring 483. When pressure is supplied via line 481 to the bore, it alsoflows through restriction 485 to the space 486 between the regulatorvalve and plug to enlarge this space to increase the spring force togradually increase the pressure line first and reverse drive trimmervalve 461.

The third speed trimmer valve 496 has the same construction andfunction. Primed numbers from the second speed have been used toindicate like parts. This valve controls the third brake apply line 436pressure which is connected by branch 497 and acts on the land a ofregulator valve element 477 which moves to open exhaust 488'. Thetrimmer regulator pressure line 452 is connected to port 489'. Thefourth clutch trimmer valve 501 is similar to the above trimmer valvesand functions in the same way and thus the same reference numerals withdouble primes have been used.

The fourth clutch trimmer valve 501 regulates the fourth clutch pressurein line 432 and exhausts the excess to exhaust 488" and is controlled bytrimmer regulator pressure from line 452 connected to port 489".

OPERATION When the engine driving this transmission is running, thetransmission input driven pump 112, FIG. 6, supplies fluid underpressure to the main line 117 which is regulated at a normal linepressure value, i.e. 150 psi when the transmission is in forward driveand forward drive knockdown pressure is supplied via line 135 to theregulator valve and at a higher reverse drive pressure i.e. 250 psi inreverse drive when this knockdown pressure is not supplied. Theregulator valve exhaust line 136 is connected through coupling feed line146 and coupling bypass valve 150 to the lubrication line 138 whichlubricates the transmission gearing.

In neutral position, the manual selector valve 191 supplies fluid to theforward knockdown line 135 and the signal feed line 194 and the otherlines, reverse 195, first 198, second 199 and third 201 drive lines areconnected to exhausts 196 or 202 directly, while the drive four line 203is connected to the hold feed line 204 and both are exhausted via thehold regulator valve 209 and the drive three feed line 201 to exhaust202. As explained above, the trimmer regulator valve 441 will supplytrimmer regulator pressure to line 452, the modulator pressure regulatorvalve 241 will provide modulator pressure in line 248 inverselyproportional to engine load and the transmission output governor valve223 will provide a governor signal in line 236 that is a function ofoutput speed. The hold pressure regulator valve is not supplied and thusthere is no hold pressure in line 217 and there is no detent pressure inline 174.

Normally when the selector valve is in neutral position the output ofvehicle driven thereby will be stationary or nearly so and the engine isrunning to pressurize the system as'pointed out above, the governorpressure and modulator pressure will be insufficient to overcome thedownshift bias of the springs so the onetwo, two-three and three-fourshift signal valves 316, 341 and 358 will be in the downshift positionconnecting the first speed apply one-two, two-three and threefour shiftsignal lines 322, 354 and 371 to exhausts 323, 353 and 372respectively.The main line 117 is directly connected to each shift signal valve andblocked by land b thereof. Since there are no shift signal pressures theone-two, two-three and three-four relay valves 378, 406 and 424 arespring biased to the downshift or lower speed position. Since there isno pressure in reverse line 195 or drive four line 203 the NJ shiftsignal valve 286 is spring biased to the neutral position and the N-lrelay valve 298 is pressure biased to the neutral position so thatsignal line 309 is connected to exhaust 314.

If the output or vehicle is coasting at higher speeds, with the selectorvalve 191 inadvertently in neutral and the engine running the automaticoutput governor and modulator pressure control system will function asduring automatic shifting described below to position the shift signalvalves and relay valves in accordance with speed and torquedemand. Whenthe one-two relay valve 378 upshifts, first brake apply line 309 isconnected by the neutral-one relay valve 298 to the line 307 which isconnected by the one-two relay valve 378 to exhaust 402 to disengage thefirst brake 89. Since drive four line 203 is exhausted at the selectorvalve in neutral position, the second and third brakes and fourth clutchcannot be applied. Thus on movement of the selector valve to a driveposition, the forward clutch will be engaged and the priority valve 392will supply fluid to then engage the drive speed selected by theautomatic controls. The drive and coasting shift engagement sequence isthe same, the drive always being completed by the first, second third orfourth speed engagement device.

On shifting the manual selector valve 191 to the drive four position DR4at the output speeds and engine load values insufficient to upshift theone-two shift signal valve 316, the main line 117 is directly connectedto the drive four line 203 to supply fluid to the N-l shift signal valve286 to vent the pressure in line 292 to permit the N-1 relay valve 298to assume the first speed position to engage the first brake 89. Sincethe coupling is driving the sun gear 38 the transmission will driveforward in first gear. Thus when the output or vehicle is standing thefirst brake 89 is engaged and the power turbine is permitted to rotatesince the coupling provides a slipping connection between the engine andthe gear train. The drive four line supplies fluid to the priority valve392 which feeds the drive four priority line 393 which in the firstspeed position of the one-two relay valve 378 is blocked by land b.

The otherdrive establishing devices are exhausted to disestablish theother drives. The second speed brake apply line 419 is connected by thedownshifted twothree relay valve 406 to one-two shift feed line 398which is connected by downshifted one-two relay valve 378 to the exhaustline 306 for disestablishing the second speed brake 82. The third speedbrake apply line 436 is connected by the downshifted three-four relayvalve 424 to the restricted branch 435 and twothree shift feed line 415which is connected by the downshifted two-three relay valve to theexhaust branch 416 and line 306 to disengage third brake 76. The fourthspeed clutch apply line 432 is connected via the downshifted three-fourrelay valve 424 to the reverse line which is connected to exhaust at theselector valve 191 to disengage the fourth clutch 63. The forward clutch51 is exhausted via the lock-up valve 271.

When the speed of the vehicle has increased suffrciently, the governorpressure in line 236 will cause the lock-up valve 271 to upshift. Whenthis occurs, the lock-up apply. line 281 will be connected to main line117, thereby pressurizing the forward clutch 51. With the lock-up clutch51 engaged the drive from the engine bypasses the coupling to directlydrive the sun gear 38 and ring gear 44. Thus, the coupling is effectiveonly during initial acceleration of the vehicle until lock-up signalvalve 316 against the spring bias reduced by modulator pressure fromline 248, the exhaust 323 is closed and the main line 117' suppliespressure to the one-two shift signal line 322 which acts in chamber 401to upshift the one-two relay valve 378 from the downshifted positionagainst the spring bias to the upshifted position. Upshifted one-tworelay valve 378 connects the low-one shift line 307 which had engagedfirst speed via the N-one relay valve 298 to the exhaust line 306 todisengage first speed and connects the priority main line 393 betweenlands a and b to the onetwo shift feed line 398 which is connected bythe restricted branch 418 between the lands b and c of the downshiftedtwo-three relay valve 406 to the second brake apply line 419 forengagement of the second speed.

At a higher speed, governor pressure similarly upshifts the two-threeshift signal valve 341 which will disconnect the second, third shiftsignal line 354 from exhaust 353 and connect it to main line..Thesecondthird shift signal line 354 is connected to chamber 422 oftwo-three relay valve 411 to upshift this valve to the upshift positionconnecting the second brake apply line 419 by restricted exhaust 421 tothe low pressure exhaust line 306 and connects the unrestricted branch417 of the one-two shift line 398 to the second-third shift feed line415 which is connected via restricted branch 435 and between the lands band c of downshifted three-four relay. valve 424 to the third brakeapply line 436 to engage third speed drive.

At a still higher speed the governor pressure will upshift thethree-four shift signal valve 358 to disconnect the three-four shiftsignal line 371 from exhaust 372 and connect it to main line 117 tosupply pressure to the chamber 438 to upshift the three-four relay valve424. This upshifted relay valve will then connect third brake apply line436 to restricted exhaust 437 and the low pressure exhaust line 306 andconnect the twothree shift feed line 415 via restriction 434 to thefourth clutch apply line 432 to engage fourth speed drive.

Since the drive four line via the priority valve 392 and priority drivefour line 393 sequentially feeds the one-two, two-three and three-fourrelay valves only one of the first, second, third and fourth speeds canbe engaged and failure of any shift relay valve to upshift will preventengagement of all higher speed drives. Since the shift signal valvesupshift sequentially with increas' ing speeds, the drives will bechanged in this sequence.

A reduction of governor pressure and/or modulator pressure will effect adownshift of the shiftsignal valves sequentially, the three-four shiftsignal valve, the twothree shift signal valve and then the one-two shiftsignal valve to provide the reverse of the above described upshiftingoperation and thus provide downshifting in this sequence.

.Whenthe throttle pedal is in the through detent position which may beeither just prior to, at, or just beyond full throttle position throughdetent valve 162 supplies to the detent line 174 fluid at a regulatedpressure to each of the four-three shuttle valve 377, three-two shuttlevalve 357 and two-one shuttle valve 332. If the hold feed pressuresupplied by line 204 in the manual valve via the drive three line 201,drive two line 199 and drive one line 198 respectively is present in anyof these valves the detent pressure being lower will be ineffective andremain blocked. However, if the hold feed pressure is not present in anyof these valves, the detent pressure will, as explained above, move theball 333 from the detent line 335 to the hold feed pressure seat 336 andthe detent pressure will be connected to the downshift line connected tothat shuttle valve. As pointed out above, the four-three down-shift line375, the three-two downshift line 355 and the two-one downshift line 329are respectively connected to the three-four shift signal valve 358, thetwo-three shift signal valve 341 and the one-two shift signal valve 316and will provide up and downshifts of each of these shift valves at ahigher speed than the normal shift speeds and remove the normaldownshift bias by the spring modified by modulator pressure.

Movement of the manual selector valve 191 to the drive three positionDR3, in addition to supplying the previously supplied signal feed line194, forward knockdown line and drive four line 203 also feeds the holdfeed line 204 and blocks the exhaust of the drive three feed line 201.Thus the hold pressure is regulated by the hold regulator valve 291 whensupplied with main line pressure by the hold feed line 204 and supplieshold pressure via line 217 to the drive three feed line 201 which isconnected by four-three shuttle valve 377 regardless of the presence orabsence of detent pressure to the four-three downshift line 375 whichwill downshift the three-four shift signal valve at a higher speed thandetent pressure. The shift valves control the slave valvesfor shiftingthe transmission as in automatic drive but up and downshiftsfrom thirdto fourth speed occur at a higher speed. Thus normal power driving wouldbe limited to first to third speeds but coast upshifts to fourth arepermitted.

Movement of the manual selector valve 191 to the drive two position DR2will additionally interconnect the drive three line 201 to supply holdpressure to the drive two line 199 which will be connected by thethree-two shuttle valve 357 to the three-two downshift line 355 whichsimilarly acts on the two-three shift signal valve 341 to control thetwo-three relay valve 406 for shifting the transmission at a higherspeed than detent shifting, so normal power one-two shifts are providedwith coast upshifts to third and fourth.

Movement of the manual selector valve 191 to the drive one position DRladditionally connects hold pressure from drive three feed line 201 tothe drive one line 198 which is connected by the two-one shuttle valve332 to the two-one downshift signal line 329 which acts on the one-twoshift signal valve 316 to control the one-two relay valve 378 to shiftthe transmission between first and second speeds at higher speeds thanthe detent downshift to normally hold first speed but permit coastupshifts. As mentioned above, line 198 may also be connected at port 285to engage the lock-up clutch.

In order to make a shift to reverse the modulator valve must be firstmoved to neutral, placing the control system in the above describedneutral condition, and then to reverse R. ln the reverse position R theselector valve 191 exhausts the drive four line 203 and forwardknockdown line 135 through the hold feed line 204, the hold regulatorvalve 209 and drive three line 201 to exhaust 202. Exhausting theforward knockdown line 135 causes main pressure regulator valve 1 19 toincrease main line pressure in line 117 to a higher value, i.e., 250psi. The forward lock-up clutch 51, the second brake 82 and the thirdbrake 76 are exhausted. It also exhausts the normal forward drive feedthrough the relay valves, which through the two-three shift line 415with the three-four relay valve 424 upshifted feeds the fourth clutchapply line 432 or when downshifted the third brake apply line 436. Toestablish reverse drive three-four relay valve must be in thedownshifted or third speed position. Then the selector valve 191 inreverse position connects mainline 117 to reverse line 195, which withthe three-four relay valve 424 in the downshift position is connected tothe fourth clutch apply line 432 to engage the fourth clutch. Inaddition to establishing reverse the first brake 89 must be applied.Pressure in line 195 upshifts the N-l shift signal valve 286 to exhaustthe pressure bias on the NJ relay valve 298, thereby directing fluidpressure in line 307 to first apply line 309. Of course, if the 1-2relay valve 378 is up-shifted at this time, line 307 will be exhaustedthrough line 306 so that reverse drive cannot be engaged when thevehicle is moving forward in the second or higher gear ratio.

In the above description, references to a direction of the valve on thedrawing as right or left is merely for convenience and it will beappreciated that the location and relative arrangement of the valves isnot important but that they may perform the above described functions inany position.

It will be appreciated that the invention may be used in the abovedescribed preferred embodiment and modifications thereof.

1 claim:

1. A transmission and control comprising: aninput shaft; an outputshaft; multi-ratio planetary gearing means drivingly connected betweensaid input and output shafts including selectively engageable driveestablishing means for providing a plurality of drive ratios betweensaid input and output shafts including four forward ratios, a reverseratio and a neutral condition;-fluid drive means operatively connectedbetween said input shaft and said planetary gearing means for providinga fluid drive to said planetary gearing means when one of the forwardratios is effective; selectively engageable lock-up clutch means inparallel drive transmitting relation with said fluid drive means forproviding a mechanical drive to said planetary gearing means in allother of the forward drive ratios; one of said selectively engageabledrive establishing means being engaged .to provide a reaction member insaid planetary gearing means in both said one forward ratio and'saidreverse ratio; another of said selectively engageable-drive establishingmeans being engaged in the reverse ratio to directly connect said inputshaft to said planetary gearing means to provide a mechanical drive tosaid planetary gearingmeans; and control means for controlling theselective engagement of said drive establishing means and said lock-upclutch-means.

2. The invention defined in claim 1 and said control means includingmanual valve means for selecting forward, neutral and reverse driveconditions in said transmission; relay valve means shiftable in responseto movement of said manual valve means to the forward or reverseposition; and shift valve means for controlling the engagement of saidone drive establishing means during both the one forward ratio andthereverse ratio and being controlled by said relay valve means; said relayvalve means, being effective to direct control pressure to control saidshift valve means in neutral andto exhaust the control pressure fromsaid shift valve means in forward or reverse drive.

3. A transmission and control comprising: an input shaft; fluid couplingmeans for providing a fluid drive having an input member drive connectedto said input shaft and an output member; and output shaft; multiratioplanetary gearing means operatively connected between said output memberand said output shaft for providing four forward speed ratios and areverse speed ratio including first brakemeans selectively engageablefor establishing a reaction member in said gearing means in the firstforward speed ratio and the reverse speed ratio,-second and third brakemeans selectively engageable for establishing reaction members in saidgearing means for the second'and third forward ratios respectively,first clutch means selectively engageable to drive connect said inputand output members of said coupling means to provide a mechanical drivepath to said gearing means in the second and third forward speed ratios,and second clutch means selectively engageable to drive connect saidinput member with said gearing means to provide a mechanical drive tosaid gearing means during the reverse speed ratio, and cooperating withsaid first clutch means to establish a direct mechanical drive to thegearing means in the fourth forward speed ratio; and control means forcontrolling the engagement of said clutches and brakes.

4. A transmission and control comprisingzan input shaft; and outputshaft; multi-ratio planetary gearing means including selectivelyengageable drive establishing means for providing a plurality of driveratios between said input and output shafts including four forwardratios, a reverse ratio and a neutral condition; fluid drive meansoperatively connected between said input shaft and said planetarygearing means for selectively providing a fluiddrive to said planetarygearing means in said forward ratios; selectively engageable lock-upclutch means in parallel drive transmitting relation with said fluiddrive means for providing a' mechanical drive to said planetary gearingmeans in the forward drive ratios; manual means for engaging saidloek-up clutch means in one forward ratio; governor means forautomatically engaging said lock-up clutch means in said forward ratios;one of said selectively engageable drive establishing means beingengaged to establish a reaction member in said gearing means in bothsaid one forwardratio and'said reverse ratio; and another of saidselectively engageable drive establishingmeans being engaged in thereverse ratio to directly.

connect said input shaft to said planetary gearing means to provide amechanical drive to said planetary gearing means.

5. A transmission and control comprising: an input shaft; fluid"coupling means for providing a fluid drive having an input member driveconnected to said input shaft and an output member; an output shaft;multiratio planetary gearing means operatively connected between saidoutput member and said output shaft for providing four forward speedratios and a reverse speed ratio-including first brake means selectivelyengageable for establishing a reaction member in said gearing means inthe first forward speed ratio and the reverse speed ratio, second andthird brake means selectively engageable for establishing reactionmembers in said establish a split fluid-mechanical input drive to saidgearing means in the fourth forward ratio, and cooperating with saidfirst clutch means to establish a direct mechanical input drive to thegearing means in the fourth forward speed ratio; and control means forcontrolling the engagement of said clutch and brakes,

said fluid coupling means providing a fluid drive to said gearing insaid forward ratios when said first clutch means is disengaged.

1. A transmission and control comprising: an input shaft; an outputshaft; multi-ratio planetary gearing means drivingly connected betweensaid input and output shafts including selectively engageable driveestablishing means for providing a plurality of drive ratios betweensaid input and output shafts including four forward ratios, a reverseratio and a neutral condition; fluid drive means operatively connectedbetween said input shaft and said planetary gearing means for providinga fluid drive to said planetary gearing means when one of the forwardratios is effective; selectively engageable lock-up clutch means inparallel drive transmitting relation with said fluid drive means forproviding a mechanical drive to said planetary gearing means in allother of the forward drive ratios; one of said selectively engageabledrive establishing means being engaged to provide a reaction member insaid planetary gearing means in both said one forward ratio and saidreverse ratio; another of said selectively engageable drive establishingmeans being engaged in the reverse ratio to directly connect said inputshaft to said planetary gearing means to provide a mechanical drive tosaid planetary gearing means; and control means for controlling theselective engagement of said drive establishing means and said lock-upclutch means.
 1. A transmission and control comprising: an input shaft;an output shaft; multi-ratio planetary gearing means drivingly connectedbetween said input and output shafts including selectively engageabledrive establishing means for providing a plurality of drive ratiosbetween said input and output shafts including four forward ratios, areverse ratio and a neutral condition; fluid drive means operativelyconnected between said input shaft and said planetary gearing means forproviding a fluid drive to said planetary gearing means when one of theforward ratios is effective; selectively engageable lock-up clutch meansin parallel drive transmitting relation with said fluid drive means forproviding a mechanical drive to said planetary gearing means in allother of the forward drive ratios; one of said selectively engageabledrive establishing means being engaged to provide a reaction member insaid planetary gearing means in both said one forward ratio and saidreverse ratio; another of said selectively engageable drive establishingmeans being engaged in the reverse ratio to directly connect said inputshaft to said planetary gearing means to provide a mechanical drive tosaid planetary gearing means; and control means for controlling theselective engagement of said drive establishing means and said lock-upclutch means.
 2. The invention defined in claim 1 and said control meansincluding manual valve means for selecting forward, neutral and reversedrive conditions in said transmission; relay valve means shiftable inresponse to movement of said manual valve means to the forward orreverse position; and shift valve means for controlling the engagementof said one drive establishing means during both the one forward ratioand the reverse ratio and being controlled by said relay valve means;said relay valve means being effective to direct control pressure tocontrol said shift valve means in neutral and to exhaust the controlpressure from said shift valve means in forward or reverse drive.
 3. Atransmission and control comprising: an input shaft; fluid couplingmeans for providing a fluid drive having an input member drive connectedto said input shaft and an output member; and output shaft; multi-ratioplanetary gearing means operatively connected between said output memberand said output shaft for providing four forward speed ratios and areverse speed ratio including first brake means selectively engageablefor establishing a reaction member in said gearing means in the firstforward speed ratio and the reverse speed ratio, second and third brakemeans selectively engageable for establishing reaction members in saidgearing means for the second and third forward ratios respectively,first clutch means selectively engageable to drive connect said inputand output members of said coupling means to provide a mechanical drivepath to said gearing means in the second and third forward speed ratios,and second clutch means selectively engageable to drive connect saidinput member with said gearing means to provide a mechanical drive tosaid gearing means during the reverse speed ratio, and cooperating withsaid first clutch means to establish a direct mechanical drive to thegearing means in the fourth forward speed ratio; and control means forcontrolling the engagement of said clutches and brakes.
 4. Atransmission and control comprising: an input shaft; and output shaft;multi-ratio planetary gearing means including selectively engageabledrive establishing means for providing a plurality of drive ratiosbetween said input and output shafts including four forward ratios, areverse ratio and a neutral condition; fluid drive means operativelyconnected between said input shaft and said planetary gearing means forselectively providing a fluid drive To said planetary gearing means insaid forward ratios; selectively engageable lock-up clutch means inparallel drive transmitting relation with said fluid drive means forproviding a mechanical drive to said planetary gearing means in theforward drive ratios; manual means for engaging said lock-up clutchmeans in one forward ratio; governor means for automatically engagingsaid lock-up clutch means in said forward ratios; one of saidselectively engageable drive establishing means being engaged toestablish a reaction member in said gearing means in both said oneforward ratio and said reverse ratio; and another of said selectivelyengageable drive establishing means being engaged in the reverse ratioto directly connect said input shaft to said planetary gearing means toprovide a mechanical drive to said planetary gearing means.